There is also known a cassette for intra-oral dental X-ray photography, which contains an image plate sensitive to X-rays. The functioning of the selenium-containing image plate is based on the adherence of pigment to the plate surface. The disadvantage of the system is that holding the thick and rigid cassette in the mouth is cumbersome.
The object of the present invention is to provide an image plate particularly suited for intra-oral dental photography, avoiding the above-mentioned disadvantages of prior-art systems. The invention, in which the image plate is placed in a shield in a manner known per se, is characterized in that the shield has been made pervious to X-rays but impervious to visible light, and that the shield comprises a closed shielding bag of plastic membrane.